We provide the retrieved pulse for optimum wedge insertion (maximum compression) conditions and correct its time evolution due to the spectral phase having been wrongly assigned the opposite sign in our previous paper [Opt. Express 20, 17880 (2012)]. These changes do not affect the conclusions of the paper.
© 2013 OSA
We report here corrections for reference . In Section 4.1, it is said that the pulse retrieval in Figs. 4(c) and 4(d) is for the best compression achieved, whereas it actually corresponds to a non-optimal wedge position, namely the “zero” glass insertion (d = 0) in the corresponding d-scan traces in Figs. 4(a) and 4(b), where the pulse is still negatively chirped. Clearly, the maximum of the second-harmonic generation signal - directly related to the optimum compression conditions - appears shifted upwards in the traces, occurring for the insertion d = 0.7 mm. Therefore, we corrected the retrieved spectral phase with the positive dispersion introduced by the additional 0.7 mm of BK7. Also, in  we inadvertently used the opposite sign for the spectral phase, which has been corrected here. In Figs. 1(a) and 1(b), we give the pulse in the spectral and the temporal domains, respectively. These figures correct Figs. 4(c) and 4(d) in .
Notice that, as a consequence of the above corrections, the duration of the compressed pulses has now been reduced from 7.8 ± 0.1 fs to 7.3 ± 0.1 fs (FWHM) due to considering optimum compression (d = 0.7 mm) conditions instead of the previous “zero” glass insertion (d = 0). Also, the corrected spectral phase sign implies that the retrieval has in fact a post-pulse (Fig. 1(b)) instead of a pre-pulse.
These corrections do not affect the spectral amplitude and the wavefront results given in Fig. 5 of . However, the results in Fig. 6 of  will differ. The overall spatial evolution along the focusing region is the same, although the temporal dependence of the pulse now corresponds to a shorter pulse followed by a post-pulse (the correct results are given in Fig. 2 ), similarly to the temporal dependence shown here in Fig. 1(b).
Regarding the on-axis comparison of Section 4.3, it is affected equivalently. Figure 7 in the original manuscript is corrected here by Fig. 3 . Therefore, the average pulse duration on-axis is reduced from 8.0 ± 0.3 fs to 7.5 ± 0.2 fs (Fig. 3(c)). Again, the temporal profile corresponds to a post-pulse (see Figs. 3(c) and 3(d)), as obtained from the spectral phase given in Fig. 3(a). Consequently, the on-axis pulse duration as a function of the propagation distance (red curve in Fig. 3(b)) is reduced by ~0.5 fs with respect to .
The calculated values of the peak irradiance (Section 4.4) are slightly modified due to the temporal duration correction. The correct values obtained at the focus are , and in the Gaussian irradiance approximation, for the measured spatiotemporal irradiance from the sets and , respectively. Consequently, the curves in Fig. 8 are re-scaled by these peak values.
We apologize for the errors in our paper . These corrections are consequence only of the rectification of the spectral phase of the reference pulse and do not affect the main purpose of the paper nor its conclusions.
References and links
2. M. Miranda, C. L. Arnold, T. Fordell, F. Silva, B. Alonso, R. Weigand, A. L’Huillier, and H. Crespo, “Characterization of broadband few-cycle laser pulses with the d-scan technique,” Opt. Express 20(17), 18732–18743 (2012). [CrossRef] [PubMed]
3. B. Alonso, R. Borrego-Varillas, O. Mendoza-Yero, Í. J. Sola, J. S. Román, G. Mínguez-Vega, and L. Roso, “Frequency resolved wavefront retrieval and dynamics of diffractive focused ultrashort pulses,” J. Opt. Soc. Am. B 29(8), 1993–2000 (2012). [CrossRef]